Pre-op assessment Flashcards
There can be significant ‘trauma’ associated with surgery and when assessing whether a patient is fit for surgery we have to considered these responses. Give examples of trauma caused by surgery
- Stress response - increased secretion of pituitary hormones (cortisol) and catecholamines from adrenals and activation of the sympathetic N.S
- Fluid shifts
- Blood loss
- Strain on systems - CV, Resp and Renal systems in particular
- Metabolic changes
What are potential anaesthetic problems?
- Airway - will there be any difficulties if have to intubate etc
- Spine - deformities? previous surgery? may effect whether a spinal anaesthetic or epidural can be done
- Reflux/not fasted - risk of aspiration
- Obesity - cause difficulties like IV access or well fitting BP cuff (true BP monitoring)
- Rarities / Family history
- Malignant hyperpyrexia
- Cholinesterase deficiency
What are some investigations that might be done to assess whether a patient is fit for surgery (and therefore anaesthesia)?
Cardiovascular
- ECG
- Exercise tolerance test
- Echo
- Myocardial perfusion scan
- Stress echo
- Cardiac catheterisation
- CT coronary angiogram
Respiratory
- Saturations
- ABG
- CXR
- Peak flow measurements
- FVC/FEV
- Gas transfer
- CT chest
Why do we do investigations on patients before coming in for surgery?
- Detect unknown conditions/ Diagnose suspected conditions
- To target those at risk
- Find out severity of known disease
- Establishing a baseline
- Detecting complications
- Assessing risk
- Guiding management
- Documenting improvement
What is ASA Grading?
A scale used to identify how healthy/fit or how sick a patient is:
- ASA1 Otherwise healthy patient
- ASA2 Mild to moderate systemic disturbance
- ASA3 Severe systemic disturbance
- ASA4 Life threatening disease
- ASA5 Moribund patient
- Now an (ASA6 Organ retrieval)
Not very specific - obese patient who smokes could be ASA1 where as a fit, young athlete with mild asthma could be ASA2
Cardiac risk index
Commonly used along with ASA grading
You get 1 point for each:
- High risk surgery
- Ischaemic heart disease
- Congestive heart failure
- Cerebrovascular disease
- Diabetes
- Renal failure
2 or more puts you at higher risk.
Exercise tolerance score
Ask the patient if you can do the following activities without getting breathless:
- Walk around the house 2 METS
- Do light housework 3 METS
- Walk 100-200 metres on the flat 4 METS
- Climb a flight of stairs or walk up a hill 5 METS
- Walk on the flat at a brisk pace 6 METS
- Play golf, mountain walk dance, or any form of exercise 7 METS
- Run a short distance 8 METS
- Do either strenuous exercise or heavy physical work 9 METS
METS = metabolic equivalent of task
This determines whether patient will be able to deal with stress of surgery
Very subjective - patient may lie to get the surgery
What is considered the ‘gold standard’ method for assessing patient fitness for surgery?
Cardiopulmonary exercise testing - done in a lab
